Containers for chilling the contents therein to a desired temperature and then maintaining the contents at that temperature have been known for some time. However, these containers are normally relatively large and rely on cyclic refrigeration to maintain the contents of the container at the desired temperature. The cyclic refrigeration requires the use of electricity for its operation. There exists a need to maintain certain items, such as foodstuffs, at a desired temperature in areas where electricity is not readily available. For example, when traveling in an automobile, when traveling in a relatively small watercraft and when in a remote location, such as on a picnic.
A common remedy to the problem of maintaining items, such as foodstuffs, at a desired temperature is to place the items and ice in a portable insulated container. Ice chests are commonly used for this task. However, ice does not stay frozen for extended periods of time and, if the container is not well insulated, the ice will melt rapidly and the contents of the container will not be maintained at the desired temperature. Dry ice or frozen carbon dioxide has been utilized in place of ice or frozen water to maintain the contents of a container at a relatively low temperature for an extended period of time. However, there are drawbacks to the use of dry ice. It is relatively expensive. It can cause damage to the skin when not handled properly. It is not readily available.
Accordingly, there exists a need for a portable container constructed to substantially reduce thermal conductivity between the exterior and interior of the portable container. This new and improved construction would enable the container to keep and maintain the contents thereof at a desired temperature for an extended period of time. Also, the means to maintain the temperature within the container should be relatively inexpensive and readily available.